"It's tomorrow," Richie deadpanned, when asked by Ryan Seacrest on the Oscar red carpet if she and Madden had picked a wedding date. But Madden, who is set to deejay inside the ceremony, joked that he wanted to do it right after the telecast. "I thought it [would] be cool to do it here," the rocker said.

While Richie joked with Seacrest that she'd love him to "get ordained" and marry the couple, the starlet was less direct when pushed for more details about the nuptials. And her fiancé was equally tight-lipped.

"The same thing as our engagement," he said of immediate wedding plans, "we're kind of doing it at our own pace. We have no idea right now." Teased Richie: "Like he has any say."

So, will it be a big ceremony – or something small and private? That's another source of (loving) disagreement. "According to her [we'll have a] really big [wedding]," Madden said. "According to me, [it will be] really small."

One thing Madden did disclose: Details from his deejay set. Though he initially said he'd keep his set list a secret, the musician told Seacrest he was excited to be "entertaining the crowd in between all the production. I'm doing a lot of old school Motown [tunes]," he said.